In this paper, we have examined the activity and selectivity of catalysts for the one-step, gas phase production of methyl isobutyl ketone (MIBK) from acetone (propanone) over the temperature range 373-573 K. The catalysts used were an impregnated MgO/silica, a Pd-MgO/silica formed from coimpregnation of the nitrates, and a Pd supported on a 1% Mg doped silica, Pd/Mg-SiO 2 . Using MgO/silica, mesityl oxide (MO) was formed with 100% selectivity at 373 and 473 K. Addition of Pd gave 100% selectivity to MIBK at 373 K, albeit at low conversion. Pd-MgO/silica revealed a promotional effect of the MgO on the hydrogenation function of the Pd and a promotional effect of the Pd on the aldol condensation activity of the MgO. The Pd/Mg-SiO 2 catalyst showed high selectivity but low conversion, as no promoting effect was observed.

The transhydrogenation of propyne and butane was studied over a 1 % VO x /alumina catalyst at 873 K. In the absence of the vanadia, the alumina support was active for cracking and alkylation. However, the addition of the vanadia reduced the propensity for both cracking and alkylation and added dehydrogenation activity. When propyne and butane were co-fed over the catalyst there was a synergistic effect resulting in an increased conversion of propyne (81 cf. 26 % when fed alone); however, much of this increased conversion was converted to carbon deposited on the catalyst. Transhydrogenation of propyne to propene was detected with an enhanced yield of propene when the propane/butane mix was passed over the catalyst. Taking a yield based on propyne fed then the yield of propene increased from 1.2 to 5.0 %. The conversion of butane to value-added products was also enhanced with all the butane converted accounted for in the production of 1-butene, trans-2-butene, iso-butane and iso-butene.

The general objectives of this research were to investigate the effect of the support and the gas atmosphere on the decomposition and reduction of cobalt nitrate hexahydrate supported on silica and alumina to gain a greater understanding of the calcination and reduction procedures used in catalyst manufacturing processes. The decomposition was followed by TGA-DSC-MS. The observed breakdown on the unsupported complex is similar but not identical to previous reports with NO detected as an evolved gas. In an oxygen/argon atmosphere the decomposition is generally simplified for the supported samples with a fewer number of weight loss events. When supported on alumina, cobalt nitrate is stabilised with decomposition events shifting to higher temperatures, whereas when supported on silica, cobalt nitrate is destabilised with only one significant decomposition event, which occurs at a lower temperature than that of the unsupported complex. In a hydrogen/nitrogen atmosphere partial decomposition of cobalt nitrate occurs before reduction is initiated with both supported samples. When supported on alumina, cobalt nitrate reduction is catalysed with the two events that occur below 350°C happening at lower temperatures, while reduction above 350°C is moved to higher temperatures. The silica-supported complex in contrast exhibits reduction events that are all reduced in temperature relative to the unsupported salt. However, there is evidence of the formation of cobalt silicate with a high temperature reduction. The study has shown that the calcination and direct reduction of supported cobalt nitrate is significantly affected by the support and that different conditions are required to achieve the same state.

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